Agent parameters
[Agent] parameters influence whether and how the High-speed Apply Engine performs multi-threaded execution in your environment. By adjusting these parameters, you can influence how many agents High-speed Apply Engine uses to process your apply request.
Parameter | Reference |
---|---|
InitialAgents | |
MaxAgents | |
MaxPrepares |
The following figure shows an example of the [Agent] parameters.
[Agent]
InitialAgents=2
MaxAgents=10
MaxPrepares=50
InitialAgents=2
MaxAgents=10
MaxPrepares=50
High-speed Apply Engine provides multi-threaded execution to increase parallelism and improve the overall performance of an apply request. Using more agents can often improve performance, but several factors affect this general rule.
- The distribution of work in your input greatly influences performance. Distribution can reduce or eliminate the advantages of multiple agents. For example, if ninety percent of your input affects one table and your configuration parameters require that the same agent process all updates to that table, additional agents provide little benefit.
- High-speed Apply Engine uses only the number of agents that it needs to complete an apply request. You can specify a minimum and maximum number of agents, but the actual number that High-speed Apply Engine uses depends on the following criteria:
- Type of processing that is required by the request
- Number of unique objects that are affected by the request
- How the target objects are grouped (for example, by referential integrity or data sharing requirements)
Be aware of the following points regarding the [Agent] parameters:
- Each agent that High-speed Apply Engine uses requires a separate connection to the target database (for Db2 on mainframe targets, a separate thread on the Db2 subsystem). Consider how your [Agent] parameters match the number of connections available in your environment. In some environments, the number of connections is constrained by workload or policy.
- The AIX operating system limits the amount of shared memory segments that any one process can have. For Db2 LUW on AIX, you can have only up to 8 agents.
- Under distribution by UR, High-speed Apply Engine is more likely to use the maximum number of agents available (especially if your input contains a large number of transactions with many dependencies between them). Use the MaxAgents parameter to prevent High-speed Apply Engine from using more database connections than your environment can tolerate. (For more information, see MaxAgents.)
Related topic
Tip: For faster searching, add an asterisk to the end of your partial query. Example: cert*